Identifying, Protecting, & Enhancing
Climate Refugia for Salmonids
Dan Isaak & Mike Young
US Forest Service Research
The New Reality…
1880-2014 Global Air Temperature Trend
2014 Set a
New Record
Timing Shift
Average change
+2.3 days/decade
No Change
100s of Studies Show Phenology
Shifts in Many Plants & Animals
Parmesan and Yohe. 2003. Nature 421:37-42.
Species Distributions are
Shifting Towards Cooler Areas
Elevation
Average distribution shift
6.1 km/decade poleward
OR
6.1 m/decade higher elevation
Time 2
Stream Distance
Parmesan and Yohe. 2003. Nature 421:37-42.
Summer Air Temp Trends (1968–2011)
~0.21ºC/decade
Weather
Stations
OWSC Climate Tool map
http://www.climate.washington.edu/trendanalysis/
River Temp Trends (1968-2011)
245 sites with >10 year monitoring records
+0.11°C/decade
98.5% sites are warming
Isaak et al. In Prep.
Fish are Trying to Follow Climate
Flow (m3/s)
x
Advance rate = 1.5 days/decade
July Temp (˚C)
Median
Passage date
Sockeye Migrations Happening Earlier…
Crozier et al. 2011. A Case Study of a
Year
Shift toward Earlier Migration Date
in Sockeye Salmon. The American Naturalist 178:755-773.
PDO Index
Climate Cycles (PDO & ENSO)
Jack is Back
The Blob Ate Last Year’s Snow
Record Low Snow…
2015 Was a “Perfect storm”
Lots of Fish, Lots of Mortalities
Climate change is tilting the odds
towards more perfect storms
How Much Warmer & When?
The Future is Uncertain…
CMIP5?
AR4?
The Specifics are
an “Unknowable
Unknown”
A Wetter or Drier Future?
Total Precip % Change
Predictions are less certain
0
Total Annual flow
BUT…Total Annual Flow & Low Flows
Have Been Decreasing
(1948-2006)
(Luce and Holden 2009)
Decreasing Wind Speeds & Total
Precipitation at High Elevations
≠
C
-4
-3
-2
-1
0
1
2
3
4
Future wind speed
Historic wind speed
c)
Annual Precipitation
(1950-2009)
mm
Year
-25 -20 -15 -10 -5
0
5
10 15 20 25
Identifying & Protecting Climate Refuge
Habitats Hedges Against Uncertainty
Strategic Context for
Investment Planning
I’m going to invest here…
…not here
Resolving Refugia Requires High-Resolution
Climate Scenarios Where Fish Live
Climate model (air temp & precip)
Regional patterns
Stream temperatures & flow
Stream reach
patterns
VIC
Resolving Refugia Requires High-Resolution
Climate Scenarios Where Fish Live
Climate model (air temp & precip)
Regional patterns
Stream temperatures & flow
Stream reach
patterns
VIC
Lots of Stream Temp Data in the PNW
>150,000,000 hourly records
>15,000 unique stream sites
>100 resource agencies
High-Resolution Stream Scenarios
• R2 = 0.91
• RMSE = 1.0ºC
1-km
resolution
Website Distributes Scenarios &
Data in User-Friendly Formats
1) GIS shapefiles of stream
temperature scenarios
3) Temperature data summaries
2) GIS shapefiles of stream temperature
model prediction precision
+ = Thermograph
= Prediction SE
Google “NorWeST” or go here…
http://www.fs.fed.us/rm/boise/AWAE/projects/NorWeST.shtml
Stream Scenarios Enable Accurate Fish
BIG FISH DATA
Distribution Models
13,000 sample
sites
Isaak et al. 2015. The cold-water climate shield: Delineating refugia for preserving
native trout through the 21st Century. Global Change Biology 21:2540-2553.
Bull Trout Climate Probability Map 1980s
Stream scale
predictions
Population Occurrence
5,332 >0.1 habitats
1,325 >0.5 habitats
348 >0.9 habitats
Bull Trout Climate Probability Map 2040s
Population Occurrence
3,304 >0.1 habitats
641 >0.5 habitats
130 >0.9 habitats
Bull Trout Climate Probability Map 2080s
North Cascades
Flathead
Walla Walla
Metolius
Central
Idaho
Population Occurrence
Worst
case
scenario!
2,712 >0.1 habitats
460 >0.5 habitats
62 >0.9 habitats
Website Distributes Precise
Digital Climate Habitat Maps…
Climate Shield website:
http://www.fs.fed.us/rm/boise/AWAE/projects/ClimateShield.html
Presentations &
Publications
Digital Maps &
ArcGIS Shapefiles
Fish Data
Sources
Distribution
Monitoring
File formats:
15 Scenarios:
• ArcGIS files
• pdf files
• 3 climate periods
• 5 Brook invasion levels
Many Conservation Investment
Options Once we Know “Where”
•Maintaining/restoring flow…
•Maintaining/restoring riparian…
•Restoring channel form/function…
•Prescribed burns limit wildfire risks…
•Non-native species control…
•Improve/impede fish passage…
I’m going to invest here…
…not here
Refuge Concept for Big Fish in Big Rivers
25,000 kilometers
222,000 kilometers
• Abundant high elevation
refuges
• Body size not limiting
• Life cycle includes small
areas
An Application with Salmon
Spatial variation in pre-spawn mortality
Bowerman, Keefer, & Caudill (U. Idaho)
An Application with Salmon
Spatial variation in pre-spawn mortality
Bowerman, Keefer, & Caudill (U. Idaho)
Small & Medium Size Rivers
Cooling
Shading is THE most
important factor…
Heating
Riparian Vegetation Restoration Can Help
Webb et al. 2008 Month of the Year
More Summer Water Keeps Streams Cooler
Many Straws
in the Drink…
Diversion
sites
Modernize Water
Systems for
Efficiency…
Purchase Water Rights
Some Cool Salmon Rivers Blocked
Cool
Warm
Cold Micro-refugia are Important Migration
Waypoints Why Not Map Them all in PNW Rivers?
Technology exists & becoming cheaper…
Drone
mounted
cameras
Torgersen et al. 1999; 2012
Some Rivers Already Have Thermal Imagery
Website & User-Friendly
Digital Formats Needed to
Provide Access…
Fullerton et al. 2015
Protecting Something Requires Knowing Where it Is…
Options for Cooling Largest Rivers
are Limited…
Icebergs
Artificial Icebergs
Lower Clearwater
20
18
16
14
Deep reservoir needed
for cold water creation
12
10
1979
1989
1999
2009
Accelerate Evolution?
Hatchery selection of migration timing
Trait
Heat tolerance
Disease resistance
Upstream migration timing
Spawning date
Emergence date
Juvenile growth
Downstream migration timing
Ocean residence
Evolutionary Potential
Low
Low to moderate
High
High
Low
Low
?
?
Crozier et al. 2008
Extinction not
happening
% Escapement
Biocomplexity Will Buffer Future Changes
…But some species (or runs) will experience
long-term declines in abundance
Summer runs
Fall/winter runs
Integrate Salmon Life Cycle Models &
Stream Climate Scenarios
Spatially explicit
predictions for
investment planning…
A Different Mindset is Required…
We can’t save everything
Sorry
Charlie
Inter-Disciplinary, Inter-Agency Spirit
will Be Needed…
PNW is a World Leader
Collaborative
solutions
Inter-Generational Commitment
This can be our
Finest Century
The End
Identifying, protecting, and enhancing climate refugia for
salmonids
Dan Isaak and Mike Young, US Forest Service
Climate change in the PNW has been gradually warming rivers and reducing
snowpacks and runoff for several decades. Those trends are likely to continue for the
next several decades and maybe longer depending on the evolution of human energy
economies and future greenhouse gas emissions. Climate cycles associated with the
Pacific Decadal Oscillation and El Nino will periodically dampen or exacerbate
environmental trends, but populations of salmon and trout that require cold water to
survive will be subject to increasing amounts of thermal stress for the foreseeable
future. Many populations of resident salmonid species like bull trout or cutthroat trout
that live in steep, cold headwater streams can persist simply by shifting their
distributions towards higher elevation refuge habitats. But adaptation is more
challenging for populations of anadromous fish that migrate through large rivers
during warm periods. Warming trends of those rivers are difficult or impossible to stop
so shifts in migration timing by natural and hatchery selection are needed. Near
spawning grounds, habitat restoration strategies that maximize riparian vegetation
shade or instream flows may be beneficial. Facilitating access of anadromous fish to
cooler river habitats that are blocked by dams or natural barriers could also be a viable